Keypad assembly for portable radiotelephone and method of controlling the same

ABSTRACT

A keypad assembly for a portable radiotelephone and a method for controlling the keypad assembly. The keypad assembly includes: a printed circuit board having a plurality of metal domes; a keypad rubber disposed on the printed circuit board and having bosses formed integratedly on the positions corresponding to the respective metal domes; a sensing means disposed on the keypad rubber; and a key button part disposed on the sensing means, such that a touch screen function using the sensing means or a key button function electrically contacting the metal domes is selectively used according to the mode of the radiotelephone.

PRIORITY

[0001] This application claims priority to an application entitled“KEYPAD ASSEMBLY FOR PORTABLE RADIOTELEPHONE AND CONTROLLING METHODTHEREOF” filed before the Korean Intellectual Property Office on Oct.18, 2002 and assigned as Serial No. 2002-63778, the contents of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a keypad assembly for a portableradiotelephone, and more particularly, to a keypad assembly for aportable radiotelephone wherein a keypad can also be used as a touchscreen panel, and a method of controlling the same.

[0004] 2. Description of the Prior Art

[0005] Recently, owing to the development of the electroniccommunication industry, mobile radio communication equipment such ascellular phones, PDAs, and portable PCs have been rapidly developed totransmit or receive data and to use content in various multimediaenvironments. In particular, in the portable radiotelephone widely knownas cellular phone, the display device has been widened in many modelsfor the user's convenient carrying and the accommodation of variousfunctions. It has also been found that a keypad assembly used as a keyinput means can accommodate various functions through a mode shift.

[0006] A portable radiotelephone can employ a touch screen mode or akeypad assembly as the key input means for inputting data or thetelephone numbers of other parties. In particular, the keypad assemblyemploys a method of applying a signal, wherein the bosses, which areformed under the keypad rubber with a plurality of key buttonsintegrally formed, press the metal domes mounted on the printed circuitboard of the body. The metal domes are then electrically contacted withthe carbon contacts of the printed circuit board.

[0007] In a method wherein the touch screen mode is employed instead ofthe keypad assembly, a user employs input means such as a stylus pen.

[0008] The convenience of using a radiotelephone is furthered byemploying the keypad assembly and simultaneously employing a display fora touch screen.

[0009] Recently, in some models of radiotelephone, a dummy keypad with akeypad printed thereon has been hingedly installed between body andfolder or between body and flip, while the above touch screen mode hasbeen left unchanged. When using the dummy keypad of the radiotelephone,the dummy keypad is laid on the touch screen, and then the numeralbuttons are pressed. Thus, the inconvenience of manipulating a styluspen to use the touch screen can be avoided.

[0010] As described above, however, in the case of using a touch screenwhich does not occupy the body of the radiotelephone, there may be theinconvenience of using a stylus pen. Further, in the case of using thedummy keypad, the radiotelephone is thickened by the thickness of thedummy keypad, which is contrary to the beneficial trend towards thinnerand lighter radiotelephones. Also, in the case of using the dummykeypad, there is a problem of moving the dummy keypad to the display.

SUMMARY OF THE INVENTION

[0011] Accordingly, the present invention is directed to a keypadassembly for a portable radiotelephone which substantially obviates saidproblems due to limitations and disadvantages of the related art.

[0012] An object of the present invention is to provide a keypadassembly for a portable radiotelephone wherein a keypad can also be usedas a touch screen panel, and a method of controlling the same.

[0013] Another object of the present invention is to provide a keypadassembly for a portable radiotelephone wherein a keypad can also be usedas a touch screen panel without increasing the volume of theradiotelephone, and a method of controlling the same.

[0014] Further, another object of the present invention is to provide akeypad assembly for a portable radiotelephone and a method ofcontrolling the same, in which when the keypad assembly is used for atouch screen function, it is unnecessary to employ an input means suchas a stylus pen.

[0015] Still another object of the present invention is to provide akeypad assembly for a portable radiotelephone and a method ofcontrolling the same, in which a keypad is provided with a sensor sothat it can be used as a touch screen panel when shifting a mode.

[0016] To achieve the above objects and other advantages, according toone aspect of the present invention, there is provided a keypad assemblyfor a portable radiotelephone, which includes: a printed circuit boardhaving a plurality of metal domes; a keypad rubber disposed on theprinted circuit board and having bosses formed integratedly on positionscorresponding to the respective metal domes; a sensing means disposed onthe keypad rubber; and a key button part disposed on the sensing means,whereby a touch screen function using the sensing means or a key buttonfunction electrically contacting the metal domes is selectively usedaccording to the mode of the radiotelephone.

[0017] In other words, the present invention may employ the key buttonfunction, or may instead employ the keypad as the touch screen byshifting the mode. This is a concept contrary to a conventional numeralkeypad displayed on a touch screen, and requires no separate input meanssuch as a stylus pen. In addition, the entire keypad may be used as thetouch screen by mode shifting.

[0018] The key button assembly for a portable radiotelephone having theabove constitution includes an input unit having a keypad that can alsobe used as a touch screen panel; a control unit for generating a controlsignal to operate the input unit as the touch screen panel or as thekeypad depending on the user's setting; and a driving power supply unitfor exclusively providing a driving power to the touch screen panel orthe keypad according to the control signal from the control unit.

[0019] The key button assembly may further include a characterrecognition unit for converting a coordinate value produced from theinput unit by user's contacting with the upper surface of the panel intoa character code, if the input unit serves as the touch screen panel.The key button assembly may also further comprise a display unit fordisplaying a character according to the character code from thecharacter recognition unit on a display window. The display unit may bea display of the radiotelephone employing an LCD module.

[0020] According to another aspect of the present invention, in aportable radiotelephone including a keypad assembly that can be used asa touch screen, a method of exclusively operating the touch screen panelor the keypad includes the steps of: determining whether or not an inputmode shift key is inputted; shifting an input mode into a touch screeninput mode if the input mode shift key is inputted; cutting off adriving power supplied to the keypad, and supplying the driving power tothe touch screen panel.

[0021] It is to be understood that both the foregoing generaldescription and the following detailed description of the presentinvention are exemplary and explanatory and are intended to providefurther explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiment(s) of theinvention and together with the description serve to explain theprinciple of the invention. In the drawings:

[0023]FIG. 1 is a perspective view of a portable radiotelephoneaccording to an embodiment of the present invention;

[0024]FIG. 2 is a partial cross-sectional view of a keypad assemblyaccording to an embodiment of the present invention;

[0025]FIG. 3 is a perspective view of the portable radiotelephone inwhich the keypad assembly is used as the touch screen panel;

[0026]FIG. 4 is a block diagram of a portable radiotelephone accordingto an embodiment of the present invention; and

[0027]FIG. 5 is a flowchart illustrating a control process ofexclusively operating a touch screen or a keypad according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The present invention will now be explained with reference to theaccompanying drawings.

[0029]FIG. 1 is a perspective view of the portable radiotelephoneaccording to one preferred embodiment of the present invention, in whichthe portable radiotelephone 100 consists of a main body 120 and asub-body 110 hinged to the main body 120. The sub-body 110 hinged to themain body 120 may be a folder, a flip or a flip of flip-up typeradiotelephone. The folder type radiotelephone is illustrated as shownin FIG. 1.

[0030] Specifically, the folder 110 is hingedly coupled to the main body120 by a center hinge arm 111 and a side hinge arm 121 in such a waythat it may rotate on an axis ‘A’ in FIG. 1. An ear piece 130 serving asa loudspeaker is located in the upper position of the folder 110, and adisplay 140 is under the ear piece. An LCD module may be used as thedisplay 140.

[0031] A keypad assembly 150 with a plurality of numeral key buttons ispositioned on the main body 120, and a microphone 160 is positionedunder the keypad assembly 150.

[0032] In the keypad assembly 150, key buttons 156 are substantially onthe same plane, and a number or character (not shown) is printed on eachof key buttons 156. Preferably, the key buttons 156 may be integrallyformed with each other, and the key buttons may be positioned in such amanner that no spacing is therebetween, to serve as a touch screen. Inaddition, a mode shift button 170 may be provided on the upper portionof the keypad assembly 150. In accordance with the operation of the modeshift button 170 by a user, the keypad assembly 150 may be used as akeypad or as a touch screen excluding the key button function. FIG. 3 isa view illustrating an example in which the keypad assembly of theportable radiotelephone of the present invention is used as a touchscreen panel. If the user inputs a character (for example, “A”) on thesurface of the keypad assembly using his/her finger or other means, theinputted character is displayed on the display.

[0033]FIG. 2 is a partial cross-sectional view of the keypad assembly150 according to an embodiment of the present invention. The main body120 is provided with a printed circuit board 151 having a plurality ofmetal domes 152. If the keypad assembly 150 of the radiotelephone isoperated in the key button mode, the metal dome 152 functions torecognize the numeral buttons by bringing the carbon contacts of theprinted-circuit board 151 into electrical contact with each other. Ofcourse, the printed circuit board 151 can be replaced by a flexibleprinted circuit board (FPC) having metal domes, depending upon the kindand shape of the terminal.

[0034] A keypad rubber 154 is disposed on the printed circuit board 151.Bosses 155 can be protrudingly formed under the keypad rubber 154. Thebosses 155 are disposed at the predetermined positions corresponding tothe metal domes 152 formed on the printed circuit board 151. Thus, thebosses 155 press the metal domes 152 during an operation of the keypadrubber 154.

[0035] A sensing means is disposed on the keypad rubber 154. Acapacitive sensor 153 can be used as the sensing means. The capacitivesensor 153 is a sensor used for the touch screen panel, and it is widelyknown for detecting variation of capacitance occurring in the atmosphereby the interfacial polarization between a detecting electrode and thesurface of an object as the object is approaching. A piezo-electriccapacitive sensor may also be employed.

[0036] A plurality of key buttons 156 are disposed on the sensing means.The key buttons 156 can be provided with separate buttons with numeralsprinted thereon. Preferably, a film sheet on which numerals orcharacters are printed with a regular interval is used for the keybuttons. However, the present invention is not limited to using a filmsheet. In addition, in the case of separate buttons, it is preferable toallow no spacing between the buttons. Preferably, the key buttons 156are substantially on the same plane for convenient use in a touch screenmode.

[0037]FIG. 4 is a block diagram of the portable radiotelephone accordingto one preferred embodiment of the present invention.

[0038] Referring to FIG. 4, the operation of the portable radiotelephoneis controlled by a control unit 10. In particular, according to theembodiment of the present invention, the control unit 10 controls aninput unit 60 to function as a touch screen panel or as a keypadaccording to the set input mode. The control unit 10 is generally aone-chip microprocessor, and may be commercially available as a mobilestation modem (MSM) chip manufactured by Qualcomm Inc.

[0039] A memory 20 includes a volatile memory (e.g., RAM) and anonvolatile memory (e.g., flash memory and EEPROM), and stores programdata for controlling the operation of the portable radiotelephone,initial service data, and temporary data made by the operation of theportable radiotelephone.

[0040] A radio processing unit 30 implements communication between abase station and a portable radiotelephone. Specifically, the radioprocessing unit 30 converts a high frequency signal received through anantenna into a baseband signal via an intermediate frequency, andconverts the baseband signal into a digital signal to output it to thecontrol unit 10. The radio processing unit 30 converts the digitalsignal outputted from the control unit 10 into an analog signal, andconverts the analog baseband signal into the high frequency signal viathe intermediate frequency to transmit it through the antenna.

[0041] A display unit 40 displays the general state of the portableradiotelephone and the information inputted by a user on a displaywindow (e.g., liquid crystal display) under the control of the controlunit 10.

[0042] A driving power supply unit 70 generates DC voltage used in theportable radiotelephone, and is adapted to provide or to cut off the DCvoltage to a corresponding component under the control of the controlunit 10.

[0043] The input unit 60 is a user input device with a touch screenpanel 61 and a keypad 62 formed integrally. According to the presentinvention, the touch screen panel 61 or the keypad 62 is operatedexclusively from each other according to the set mode. This may beachieved by cutting off the power supplied to the touch screen panel 61or to the keypad 62. In the touch screen input mode, the input unit 60functions as a touch screen panel to provide the control unit 10 withcoordinate values produced by the contact of the upper surface of thepanel with a user's hand or writing instrument. Then, the control unit10 provides a character recognition unit 50 with the coordinate values.In the keypad input mode, the input unit 60 functions as a keypad toprovide the control unit 10 with the key input values produced when theuser applies pressure to the keys. Then, the control unit 10 analyzesthe key input values, and outputs the resulting characters to thedisplay unit 40 to display it on the display window. The detailedconstitution of the input unit 60 will now be described with referenceto the accompanying drawings.

[0044] The character recognition unit 50 has a conversion table toconvert the coordinate value produced from the touch screen panel 61into a character code, and reads the character code corresponding to thecoordinate value from the control unit 10 and outputs the character codeto the control unit 10. The control unit 10 outputs the character codeto the display unit 40 to display it on the display window.

[0045]FIG. 5 is a flowchart illustrating a control process forexclusively operating the touch screen or the keypad in the portableradiotelephone with the touch screen and the keypad formed integrallyaccording to an embodiment of the present invention. In theradiotelephone of the present embodiment, the input mode of theradiotelephone is initially set to the keypad input mode, and the inputmode of the radiotelephone is automatically reset to the initial keypadinput mode if the radiotelephone is closed and then opened during theoperation of the touch screen input mode. This is to allow users toeasily use the basic functions of the telephone. However, even if theradiotelephone is neither opened nor closed, if no key input is carriedout in the touch screen input mode during a predetermined time, theradiotelephone may be automatically reset to the keypad input mode.

[0046] Referring to FIGS. 4 and 5, in step S211, the control unit 10determines whether or not the input mode shift key is inputted by theuser. Preferably, the input mode shift key is embodied as a hot key soas to easily achieve the mode shift. The current input mode may bedisplayed at a specific region of the display window, so that the usercan easily recognize it. If input of the input mode shift key isdetected, the control unit 10 proceeds to step S213 to shift the currentinput mode to the touch screen input mode. In step S215, the controlunit 10 cuts off the driving power supplied to the keypad 62 andsupplies the driving power to the touch screen panel 61. In step S217,the control unit 10 provides the character recognition unit 50 with thecoordinate values inputted from the touch screen panel 61 and instructsthe character recognition unit 50 to analyze the coordinate values toproduce character codes. The control unit 10 provides the display unit40 with the resulting character codes outputted from the characterrecognition unit 50, and the display unit 40 displays the charactercodes on the display window. In step S221, the control unit 10determines whether or not the input mode shift key is inputted. If theinput mode shift key is not inputted, the touch screen input mode ismaintained.

[0047] If the input mode shift key is not inputted in step S211, or theinput mode shift key is inputted after carrying out the touch screeninput mode in step S221, the control unit 10 proceeds to step S223 tocarry out the keypad input mode. Thus, in step S225, the control unit 10cuts off the driving power supplied to the touch screen panel 61 andsupplies the driving power to the keypad. In step S227, the control unit10 analyzes the key input values inputted from the keypad 62 andprovides the resulting character codes to the display unit 40. Thedisplay unit 40 displays the character codes on the display window.

[0048] In the above description of the present invention, since thekeypad assembly includes a keypad which also serves as a touch screen byuse of a capacitive sensor, the entire keypad assembly can be used as atouch screen, thereby requiring no separate input means because of awide input space. In addition, since it is not necessary to use thedummy keypad in a double structure, the radiotelephone is prevented fromincreasing in volume. The conversion between the keypad and the touchscreen may be easily carried out through a simple manipulation of themode shift key.

[0049] The foregoing embodiments are merely exemplary and are not to beconstrued as limiting the present invention. The present invention'steachings can be readily applied to other types of apparatuses. Thedescription of the present invention is intended to be illustrative, andnot to limit the scope of the claims. Many alternatives, modifications,and variations will be apparent to those skilled in the art.

What is claimed is:
 1. A keypad assembly for a portable radiotelephonecomprising: a printed circuit board having a plurality of metal domes; akeypad rubber disposed on the printed circuit board and having bossesformed integrally on the positions corresponding to the plurality ofmetal domes; a sensing means disposed on the keypad rubber; and a keybutton part disposed on the sensing means, whereby a touch screenfunction using the sensing means or a key button function electricallycontacting the metal domes is selectively used according to the mode ofthe radiotelephone.
 2. The keypad assembly for a portable radiotelephoneaccording to claim 1, wherein the sensing means is a capacitive sensor.3. The keypad assembly for a portable radiotelephone according to claim1, wherein the key button part is a film sheet attached to the uppersurface of the sensing means, the film sheet having a plurality ofnumeral keys printed thereon.
 4. A portable radiotelephone comprising:an input unit having a keypad which can alternatively function as atouch screen panel; a control unit for generating a control signal tooperate the input unit as the touch screen panel or as the keypadaccording a the mode set by a user; and a power supply unit forexclusively supplying a driving power to the touch screen panel or thekeypad according to the control signal from the control unit.
 5. Theportable radiotelephone according to claim 4, further comprising acharacter recognition unit for converting a coordinate value into acharacter code when the input unit functions as the touch screen panel,the coordinate value being produced from the input unit by a user'scontacting an upper surface of the touch screen panel.
 6. The portableradiotelephone according to claim 5, further comprising a display unitfor displaying a character corresponding to the character code from thecharacter recognition unit.
 7. A method of exclusively operating a touchscreen panel or a keypad in a portable radiotelephone having a keypadwhich can alternatively function as a touch screen panel, comprising thesteps of: determiming whether or not an input mode shift key isinputted; shifting the input mode from a keypad input mode to a touchscreen input mode if the input mode shift key is inputted; and cuttingoff a driving power supplied to the keypad, and supplying the drivingpower to the touch screen panel.
 8. The method according to claim 7,further comprising the steps of: determining whether or not the inputmode shift key is inputted; shifting the input mode from a touch screeninput mode to a keypad input mode if the input mode shift key isinputted; and cutting off the driving power supplied to the touch screenpanel, and supplying the driving power to the keypad.